Flipper

ABSTRACT

A flipper is provided. The flipper includes a pocket, a blade and a strengthening structure. The pocket is for accommodating the foot of the user. The blade extends forwards from the pocket, and the strengthening structure is detachably disposed at the blade and extends to reach the front edge of the blade. The flexural strength of the strengthening structure is larger than that of the blade to constrain the swing angle of the blade relative to the pocket. By using the strengthening structure to constrain the swing angle of the blade, the flipper can not only provide a larger propulsion in the down-kicking state, but also decrease the resistance of water in the up-kicking state.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims priority to Taiwan Patent Application No. 103118014 filed on May 23 2014, which is hereby incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention provides a flipper, and more particularly, to a flipper that is strengthened in structure.

2. Descriptions of the Related Art

Flippers are commonly used in water sports. Flippers are used to increase the force receiving area when the user paddles the water especially in water diving. However, different muscle strengths can influence the force and endurance during paddling. For example, when leg muscles are in a down-kicking state, the muscles can provide a relatively large force with good endurance, so the main propulsion during water diving is provided by the water paddling action in the down-kicking state. To perform the down-kicking water paddling action repeatedly, the diver must withdraw his or her legs repeatedly in the form of up-kicking. However, muscles responsible for the up-kicking water paddling action are usually weaker, so the need of providing the same propulsion level in the up-kicking state as in the down-kicking state makes the diver liable to fatigue because the muscles responsible for the up-kicking water paddling action cannot withstand such a load.

Therefore, to balance the burden of the leg muscles between the up-kicking state and the down-kicking state, a resistance-reducing design is often adopted in conventional flippers. For example, a soft material is used or perforations are made on the surface of the blade to allow the water to flow through the flipper. Unfortunately, although these measures can reduce the resistance in the up-kicking state, they also reduce the resistance in the down-kicking state, thus, significantly reducing the propulsion.

Accordingly, a need exists in the art to provide a better solution for improvement.

SUMMARY OF THE INVENTION

An objective of the present invention is to provide a flipper which can reduce the resistance in the up-kicking state while still keeping sufficient propulsion in the down-kicking state.

To achieve the aforesaid objective, the present invention provides a flipper which comprises a pocket, a blade and a strengthening structure. The pocket is used to accommodate the foot of a user. The blade extends forwards from the pocket. The strengthening structure is detachably disposed at the blade and extends to reach the front edge of the blade. The flexural strength of the strengthening structure is larger than that of the blade to constrain the swing angle of the blade with respect to the pocket.

Because the strengthening structure constrains the swing angle of the blade, the flipper can not only provide a larger propulsion in the down-kicking state, but also decrease the resistance of water in the up-kicking state.

The detailed technology and preferred embodiments implemented for the subject invention are described in the following paragraphs accompanying the appended drawings for people skilled in this field to well appreciate the features of the claimed invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic front view of a flipper according to the first embodiment of the present invention;

FIG. 1B is a schematic back view of the flipper according to the first embodiment of the present invention;

FIG. 2 is a schematic back view of a flipper according to the second embodiment of the present invention;

FIG. 3A is a schematic front view of a flipper according to the third embodiment of the present invention;

FIG. 3B is an exploded perspective view of the flipper according to the third embodiment of the present invention;

FIG. 4A is a schematic front view of a flipper according to the fourth embodiment of the present invention;

FIG. 4B is an exploded perspective view of the flipper according to the fourth embodiment of the present invention;

FIG. 4C is a schematic view of a swing-constraining structure of the flipper according to the fourth embodiment of the present invention;

FIG. 5A is a schematic front view of a flipper according to the fifth embodiment of the present invention;

FIG. 5B is an exploded perspective view of the flipper according to the fifth embodiment of the present invention;

FIG. 5C is a schematic view of a swing-constraining structure of the flipper according to the fifth embodiment of the present invention;

FIG. 6A is a schematic front view of a flipper according to the sixth embodiment of the present invention;

FIG. 6B is an exploded perspective view of the flipper according to the sixth embodiment of the present invention;

FIG. 6C is a schematic view of a swing-constraining structure of the flipper according to the sixth embodiment of the present invention; and

FIG. 7 is a schematic perspective view of a flipper according to the seventh embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Firstly, the terms such as “front”, “left”, “right”, “top surface” and “bottom surface” used hereinbelow are defined with respect to a direction presented by the flipper when being worn by a user. In other words, the front corresponds to the same direction as the toes, the top surface corresponds to the foot instep of the user, and the bottom surface corresponds to the foot sole of the user. When the user wears the flipper, the left and the right directions of the flipper are just the same as the left and the right directions of the user.

Furthermore, the “up-kicking state” and the “down-kicking state” referred to hereinbelow are defined according to the flexural states of the flipper from the resistance of water when the user paddles the water with his or her legs. Specifically, the “down-kicking state” refers to the flexural state of the flipper when the user paddles the water with his or her legs in the direction towards which the user faces, and the “up-kicking state” refers to the flexural state of the flipper when the user paddles the water with his or her legs opposite to the direction towards which the user faces.

FIGS. 1A and 1B show a schematic front view and a schematic back view of a flipper according to the first embodiment of the present invention respectively. The present invention provides a flipper 1, which comprises a pocket 101, a blade 110 and a strengthening structure 120. The pocket 101 is adapted to accommodate the foot of the user just like a shoe or a sock, and selectively accommodates the ankle of the user. The blade 110 is roughly fan-shaped or tabular structure and extends forwards from the pocket 101.

The strengthening structure 120 is detachably disposed at the blade 110 and extends to reach the front edge of the blade 110. The strengthening structure 120 may extend beyond or somewhat behind the front edge of the blade 110. In this embodiment, the strengthening structure 120 extends just to reach the front edge of the blade 110. The strengthening structure 120 may be disposed on the top surface 111 or bottom surface 112 of the blade 110, or alternatively, there may be two strengthening structures disposed on the top surface 111 and the bottom surface 112 of the blade 110 respectively. The flexural strength of the strengthening structure 120 is larger than that of the blade 110 to constrain the swing angle of the blade 110 with respect to the pocket 101.

The strengthening structure 120 may swing with respect to the pocket 101 within the restrained swing angle; namely, the strengthening structure 120 may swing within the restrained swing angle much more easily than swing beyond the restrained swing angle. Correspondingly, being constrained by the strengthening structure 120, the blade 110 also may swing much more easily within the restrained swing angle.

The swing angles of the blade 110 or the strengthening structure 120 may further be defined as first swing angles and second swing angles. With the aforesaid structures, the first swing angle is the swing angle of the blade 110 with respect to the pocket 101 when the flipper 1 is in the down-kicking state. The first swing angle may have a maximum value of 30 degrees although it is not limited thereto; and the second swing angle is the swing angle of the blade 110 with respect to the pocket 101 when the flipper 1 is in the up-kicking state. The second swing angle may have a maximum value of 70 degrees although it is not limited thereto either. Therefore, the flipper 1 can provide a larger propulsion in the down-kicking state and decrease the resistance of water in the up-kicking state.

Because the strengthening structure 120 is detachable, the user can choose the flipper 1 to be equipped with the strengthening structure 120 or not in accordance with physical condition of the user. The flipper 1 will not be constrained by the strengthening structure 120 if the flipper 1 is not equipped with the strengthening structure 120, and the swing angle of the blade 110 with respect to the pocket 101 may exceed the first swing angle and the second swing angle.

A person skilled in the art can easily conceive the enablement of the flipper 1 without the strengthening structure 120 after referring to the following drawings, i.e. FIGS. 3B, 4B, 5B and 6B. Thus, the further details may be omitted hereinafter.

Hereinbelow, the construction of the strengthening structure will be detailed. In the flipper 1 according to the first embodiment of the present invention, as shown in FIG. 1A, the strengthening structure 120 may extend on the top surface 111. The strengthening structure 120 may have two strengthening ribs 121 which extend from the left side and right side of the pocket 101 along one of the two lateral portions of the blade 110 towards the front edge of the blade 110 respectively. The aforesaid two sides of the pocket 101 refer to the two portions of the pocket 101 to the left and the right of the user's foot when he or she wears the flipper 1. Therefore, the strengthening structure 120 can further avoid the flexure of the pocket 101 caused by water, thus saving the user more strength.

The aforesaid two lateral portions of the blade 110 refer to the left edge portion and the right edge portion of the top surface 111 of the blade 110. Therefore, when the strengthening ribs 121 of the strengthening structure 120 extend forwards from the two sides of the pocket 101 along the two lateral portions of the blade 110, the strengthening structure 120 can constrain the swing angle of the two lateral portions of the blade 110 with respect to the pocket 101. Because the middle portion of the blade 110 is not constrained by the strengthening structure 120, the middle portion will be flexed by the resistance of water when the user kicks down, thereby providing larger propulsion for the user to paddle through the water.

Furthermore, the strengthening structure 120 may further have a strengthening sheet 122. The strengthening sheet 122 is connected with the strengthening ribs 121 and can extend from the strengthening ribs 121 towards the top surface 111 of the blade 110 so that the two strengthening ribs 121 are connected integrally to the strengthening sheet 122. The strengthening sheet 122 covers the blade 110 but exposes a middle portion of the blade 110, so the middle portion can still be flexed by the resistance of water when the user kicks down.

As shown in FIG. 1B, the strengthening structure 120 of this embodiment may also be disposed on the bottom surface 112 of the blade 110. The two strengthening ribs 121 of the strengthening structure 120 can extend from the left and right sides of the pocket 101 along the two lateral parts of the bottom surface 112 of the blade 110 towards the front edge of the blade 110 respectively. The strengthening sheet 122 can extend from the strengthening ribs 121 towards the bottom surface 112 of the blade 110 and can be connected integrally to the two strengthening ribs 121 disposed on the bottom surface 112.

In this embodiment, the strengthening structure 120 may further have a strengthening layer 123 which covers the bottom of the pocket 101. In this way, the user will not be punctured by an object when he or she walks on the ground wearing the flipper 1.

To make the flexural strength of the strengthening structure 120 larger than that of the blade 110, the blade 110 and the strengthening structure 120 may optionally be made of different materials; or alternatively, the strengthening structure 120 may be made to have a larger flexural strength through the form design of the strengthening structure 120. For example, the strengthening structure 120 may be made to be thicker.

The blade 110 may be made of natural rubber, silicone rubber, thermoplastic rubber (TPR), polyvinyl chloride (PVC), synthetic vinyl resin (EVA), thermoplastic polyurethane (TPU) or a combination thereof.

The strengthening structure 120 is made of natural rubber, polycarbonate (PC), alkylbenzene sulfonate (ABS), polyoxymethylene (POM), polypropylene (PP), TPR, polyethylene (PE), PVC, polystyrene (PS), polyurethane (PU), nylon, synthetic vinyl resin (EVA) or a combination thereof.

FIG. 2 shows a schematic back view of a flipper according to the second embodiment of the present invention. The second embodiment of the present invention provides a flipper 2, which has technical features similar to the flipper of the first embodiment but differs therefrom in that: the strengthening structure 220 of the flipper 2 is disposed on the bottom surface 212 of the blade 210 and only has two strengthening ribs 221. The strengthening sheet and the strengthening layer are omitted.

The above embodiments and figures are mainly intended to disclose the form and the disposition manner of the strengthening structure. As can be readily known by those of ordinary skill in the art, changes may be made to the strengthening structure (e.g., changes in the number, the position(s), the disposition manner or the presence/absence of the strengthening sheet and the strengthening layer) without departing from the scope disclosed above.

FIGS. 3A and 3B illustrate a schematic front view and an exploded perspective view of a flipper according to the third embodiment of the present invention respectively. The third embodiment of the present invention provides a flipper 3, which has technical features similar to the flipper of the first embodiment but differs therefrom in that: the flipper 3 of the third embodiment further comprises at least one swing-constraining structure 330, and the strengthening structure 320 is affixed to the blade 310 via the swing-constraining structure 330.

More specifically, the at least one swing-constraining structure 330 consists of two swing-constraining structures 330 disposed on two sides of the pocket 301 respectively. The strengthening structure 320 and the corresponding swing-constraining structure 330 are affixed to each other. The swing-constraining structure 330 allows the strengthening structure 320 to swing within at least one swing angle with respect to the pocket 301. In other words, by means of the swing-constraining structure 330 constraining the swing angle of the strengthening structure 320 with respect to the pocket 301, the strengthening structure 320 can constrain a swing angle of the blade 310 with respect to the pocket 301. That is, the swing-constraining structure 330 can indirectly constrain the swing angle of the blade 310.

The end of the strengthening rib 321 that does not extend towards the front edge of the blade 310 is affixed to the swing-constraining structure 330. In this embodiment, the two swing-constraining structures 330 may be formed integrally with the two strengthening structures 320, but they are not limited thereto in other embodiments.

FIGS. 4A and 4B show a schematic front view and an exploded perspective view of a flipper according to the fourth embodiment of the present invention respectively. The fourth embodiment of the present invention provides a flipper 4, which has technical features similar to the flipper of the first embodiment but differs therefrom in that: the flipper 4 of the fourth embodiment may further comprise at least one swing-constraining structure 430, and the strengthening structure 420 is affixed to the blade 410 via the swing-constraining structure 430.

More specifically, the at least one swing-constraining structure 430 consists of two swing-constraining structures 430 disposed on the left and right sides of a pocket 401 respectively. Correspondingly, the strengthening structure 420 consists of two separated strengthening structures 420, each of which has a strengthening rib 421. An end of each the strengthening rib 421 is affixed to a side of the pocket 401 via one of the swing-constraining structure 430, an other end of the strengthening rib 421 extend forwards from the side of the pocket 401 along one of the two lateral portions of the blade 410 to reach the front edge of the blade 410. Specifically, in this embodiment, the two lateral portions of the blade 410 may be distinguished as a left portion and a right portion. The strengthening rib 421 located on the left portion of the blade 410 is formed integrally with the swing-constraining structure 430 located on the left side of the pocket 401. The strengthening rib 421 located on the right portion of the blade 410 is formed integrally with the swing-constraining structure 430 located on the right side of the pocket 401.

FIG. 4C shows a schematic view of the swing-constraining structure of the flipper according to the fourth embodiment of the present invention. In this embodiment, the swing-constraining structure 430 may be disposed on the pocket 401 pivotally, but will not swing with respect to the strengthening structure 420.

The pocket 401 has two pivots 401 a that are disposed on the two sides of the pocket 401 respectively. The swing-constraining structures 430 are affixed on the pocket 401 via the respective pivots 401 a and are pivotable around the respective pivots 401 a with respect to the pocket 401. Each of the pivots 401 a further has a protrusion 401 b, and each of the swing-constraining structures 430 has a groove 430 b. The protrusion 401 b is accommodated in the groove 430 b so that the protrusion 401 b can constrain a swing angle of the swing-constraining structure 430 with respect to the pocket 401.

FIGS. 5A and 5B show a schematic front view and an exploded perspective view of a flipper according to the fifth embodiment of the present invention respectively. The fifth embodiment of the present invention provides a flipper 5, which has technical features similar to the flipper of the first embodiment but differs therefrom in that the flipper 5 of the fifth embodiment may further comprise at least one swing-constraining structure 530, and the strengthening structure 520 is affixed to the blade 510 via the swing-constraining structure 530.

More specifically, the at least one swing constraining structure 530 consists of two swing-constraining structures 530 disposed on two sides of a pocket 501 respectively. An end of a strengthening rib 521 that does not extend towards a front edge of a blade 510 has an engaging hook 521 a. The strengthening rib 521 is detachably affixed to the corresponding swing-constraining structure 530 via the engaging hook 521 a.

FIG. 5C shows a schematic view of the swing-constraining structure of the flipper according to the fifth embodiment of the present invention. In this embodiment, the swing-constraining structures 530 may be disposed on the pocket 501 detachably and pivotally, but will not swing with respect to the strengthening structure 520. The pocket 501 has two pivots (not shown) disposed on two sides of the pocket 501 respectively. The swing-constraining structures 530 are affixed to the pocket 501 via the respective pivots and are pivotable around the respective pivots with respect to the pocket 501. Therefore, in this embodiment, not only the strengthening structure 520 along with the swing-constraining structures 530 can be detached form the flipper 5, but also the strengthening structure 520 can be detached form the swing-constraining structures 530.

Each of the two sides of the pocket 501 has a protrusion 501 b and each of the swing-constraining structures 530 has a groove 530 b. The protrusion 501 b is accommodated in the groove 530 b so that the protrusion 501 b is adapted to constrain a pivotal angle of the swing-constraining structure 530 with respect to the pocket 501.

FIGS. 6A and 6B illustrate a schematic front view and an exploded perspective view of a flipper according to the sixth embodiment of the present invention respectively. The sixth embodiment of the present invention provides a flipper 6, which has technical features similar to the flipper of the first embodiment but differs therefrom in that the flipper 6 of the sixth embodiment may further comprise at least one swing-constraining structure 630, and the strengthening structure 620 is affixed to the blade 610 via the swing-constraining structure 630.

More specifically, the at least one swing-constraining structure 630 consists of a four swing-constraining structures 630 disposed on two sides of a pocket 601 in pairs. The two swing-constraining structures 630-2 that are connected to a strengthening structure 620 disposed on the bottom surface 620 are located closer to the blade 610 than the two swing-constraining structures 630-1 that are connected to a strengthening structure 620 disposed on the top surface 611.

FIG. 6C illustrates a schematic view of each of the swing-constraining structures of the flipper according to the sixth embodiment of the present invention. In this embodiment, each of the swing-constraining structures 630 is affixed to the pocket 601, and the corresponding strengthening structure 620 is pivotable with respect to the swing-constraining structure 630. Each of the swing-constraining structures 630 has a groove 630 b, and each of the strengthening ribs 621 passes through the groove 630 b to extend from the swing-constraining structure 630 towards the front edge of the blade 610, so a pivotal angle of the strengthening rib 621 is constrained by the groove 630 b.

Furthermore, the strengthening structure 620 connected to the swing-constraining structure 630-2 is constrained by the groove 630 b to have a first swing angle of 30 degrees and a second swing angle of 70 degrees. The strengthening structure 620 connected to the swing-constraining structure 630-1 is constrained by the groove 630 b to have a first swing angle of 70 degrees and, further due to the constraint from the location of the swing-constraining structure 630-2, have a second swing angle of 30 degrees.

FIG. 7 illustrates a schematic perspective view of a flipper according to the seventh embodiment of the present invention. The seventh embodiment of the present invention provides a flipper 7, which has technical features similar to the flipper of one of the first embodiment to the sixth embodiment but differs therefrom in that: a blade 710 of the flipper 7 of the seventh embodiment has two blade pieces 713 disposed abreast and extending forwards from a pocket 701. The two blade pieces 713 partially overlap each other.

Similar to the other embodiments, the strengthening structure 720 can constrain a swing angle of the blade 710 with respect to the pocket 701. In this embodiment, the blade pieces 713 can be separated from each other to allow the water to flow therethrough more easily in the up-kicking state so that the resistance of water can be further reduced.

According to the above descriptions, by using the strengthening structure to constrain the swing angle of the blade, the flipper of the present invention can not only provide larger propulsion in the down-kicking state, but also decrease the resistance of water in the up-kicking state. Thereby, the user can participate in water sports more easily.

The above disclosure is related to the detailed technical contents and inventive features thereof. People skilled in this field may proceed with a variety of modifications and replacements based on the disclosures and suggestions of the invention as described without departing from the characteristics thereof. Nevertheless, although such modifications and replacements are not fully disclosed in the above descriptions, they have substantially been covered in the following claims as appended. 

What is claimed is:
 1. A flipper, comprising: a pocket for accommodating a foot of a user; a blade extending forwards from the pocket; and a strengthening structure detachably disposed at the blade and extending to reach a front edge of the blade; wherein a flexural strength of the strengthening structure is greater than that of the blade.
 2. The flipper according to claim 1, wherein the strengthening structure is disposed on a bottom surface of the blade.
 3. The flipper according to claim 1, wherein the strengthening structure is disposed on a top surface of the blade.
 4. The flipper according to claim 1, wherein the strengthening structure is disposed on a top surface and a bottom surface of the blade.
 5. The flipper according to claim 1, wherein the strengthening structure extends from two sides of the pocket, along two lateral edges of the blade, towards the front edge of the blade.
 6. The flipper according to claim 5, wherein the strengthening structure further extends from the two lateral edges of the blade towards the top surface or the bottom surface of the blade.
 7. The flipper according to claim 5, further comprising at least one swing-constraining structure disposed on the two sides of the pocket, wherein the strengthening structure is affixed to the blade via the swing-constraining structure, and the swing-constraining structure make the strengthening structure swing within at least one swing angle with respect to the pocket.
 8. The flipper according to claim 7, wherein the at least one swing-constraining structure is two or four swing-constraining structures, and the swing-constraining structures are affixed on the pocket pivotally; each of the two sides of the pocket has a protrusion, and the protrusion is used for constraining the swing angle of the swing-constraining structure with respect to the pocket.
 9. The flipper according to claim 7, wherein the swing-constraining structure is formed integrally with the strengthening structure.
 10. The flipper according to claim 1, wherein the blade has two blade pieces disposed abreast and extending forwards from the pocket.
 11. A flipper, comprising: a pocket for accommodating a foot of a user; a blade extending forwards from the pocket; and two strengthening structures detachably disposed at the blade and extending to reach a front edge of the blade, wherein the two strengthening structures are spaced to each other, and a flexural strength of the strengthening structures is greater than that of the blade. 